Abstract: The second harmonic wave of a solid laser light which is emitted from a second harmonic wave light source is divided into a plurality of laser beams by a diffraction grating. The divided laser beams are converged on a record carrier into a plurality of light spots by an optical head. Magnetic field generating coils for applying magnetic fields to the respective light spots in accordance with the recording signals from a signal line are disposed under the record carrier. Part of the solid laser light is reflected and input to a beam splitter. Since part of the light input to the beam splitter is taken out, a stabilizer controls the output of the solid laser light from the second harmonic wave light source, parallel recording/reproduction using the plurality of light spots which are arranged on the record carrier is enabled and the formation of the plurality of light spots is effectively controlled.

Abstract: A method for producing hydrogen peroxide by electrical discharge in a material gas in which oxygen concentration is not less than 0.5% and less than 13% is disclosed in the first aspect. In the second aspect, an apparatus for producing hydrogen peroxide having a plurality of electrical discharge chambers connected in series is disclosed. In the third aspect, an apparatus in which a material gas is recycled is disclosed. In the forth aspect, an apparatus having its electrodes covered with dielectric and an electrical discharge chamber which is cooled by a cooling member. In the fifth aspect, a method for producing hydrogen peroxide having a step of inactivating radical species produced by electrical discharges is disclosed. In the sixth aspect, an apparatus having a condensation tube coated with resin with low reactivity with hydrogen peroxide is disclosed.

Abstract: A laser oscillator includes a housing which seals a laser medium gas from the atmosphere, concave mirrors (or a set of concave and convex mirrors) positioned in the housing and having the laser medium gas therebetween, an apertured mirror positioned between the concave mirror and the other concave or convex mirror on a line connecting the spherical centers of the mirrors at a predetermined angle relative to the line, and a window through which a laser beam reflected by the apertured mirror is output from the housing. The apertured mirror has a curved reflective surface, thereby simplifying the optical system in the housing and increasing the system's reliability.

Abstract: A solid state laser apparatus comprises a laser medium having a pair of optically flat surfaces confronting to each other, and side surfaces intersecting the optically flat surfaces along an optical axis, the laser medium having a rectangular cross section; heat insulators adhered to the side surfaces of the laser medium; and reflective films for shielding the thermal insulators from pumping light. A solid state laser apparatus may comprise heat conductors bonded to the side surfaces of the laser medium, the heat conductors removing heat which occurs at bonding surfaces, the amount of removed heat from the side surfaces being smaller than that from the optically flat surfaces.

Abstract: A semiconductor-laser-pumped, solid-state laser includes a semiconductor pumping laser emitting pumping light, a solid-state laser medium arranged to be excited by the pumping light, and a laser resonator structure for emitting laser light from the solid-state laser medium. The solid-state laser medium is plate shaped having a thickness less than the broadening width of he pumping light in the solid-state laser medium. The semiconductor laser is arranged close to the face of the solid-state laser medium, and the laser resonator structure has an optical axis thereof coinciding with that of the pumping light.

Abstract: A semiconductor-laser-pumped, solid-state laser includes a semiconductor pumping laser emitting pumping light, a solid-state laser medium arranged to be excited by the pumping light, and a laser resonator structure for emitting laser light from the solid-state laser medium. The solid-state laser medium is plate shaped having a thickness less than the broadening width of the pumping light in the solid-state laser medium. The semiconductor laser is arranged close to the face of the solid-state laser medium, and the laser resonator structure has optical axis coinciding with that of the pumping light.

Abstract: This invention relates to a solid laser device with a slab-shaped laser medium. One example of a solid laser device according to the invention, comprises: a slab-shaped laser medium having one pair of optically smooth surfaces confronting each other through the optical path; first and second mirrors arranged on the optical path in such a manner that the first and second mirrors are confronted with each other through the laser medium; a resonator which forms an unstable resonator in the direction of width of the laser medium, and a low order stable resonator in the direction of thickness of the laser medium; and laser beam emergence medium for taking a laser beam out of the a resonator and outputting the laser beam from the device.

Abstract: An output laser beam of an unstable laser resonator has a circular cross sectional pattern, so that a condensation thereof becomes easy, resulting in a high power beam. The circular pattern is obtained by making an expanding mirror of the resonator partially transmissible and compensating for a phase difference between laser beam portions passing through the expanding mirror and other portion of a window mirror.

Abstract: A laser machining apparatus includes a laser resonator capable of producing a laser beam having a filled-in intensity distribution pattern and a condensing device for converting the beam into a suitable beam to perform an intended machining. A device is provided for regulating phase of the laser beam to improve the condensed laser beam. The apparatus may also include a device for pulsating the beam and a device for changing a focal depth of the beam.

Abstract: A laser device comprises a laser medium, a semiconductor light-emitting element for exciting the laser medium, a reflecting surface surrounding the outer periphery of the laser medium along its optical axis, and an opening provided in a part of the reflecting surface for causing light from the semiconductor light-emitting element to be incident upon the laser medium. The laser device is improved further by providing a polarizing plate and a light guide between the light-emitting element and the laser medium and by deviating the optical axis of excitation light from the central axis of the laser medium.

Abstract: A laser device having an infrared laser medium and an aperture member disposed within a resonator in which the mode symmetry is improved. An optical resonator including a total reflecting mirror and a partial reflecting mirror disposed at opposite ends of a gap between electrodes is arranged parallel to an optical axis and orthogonal to a gas flow direction. An aperture member disposed along the optical axis between the mirrors on the side of the partial reflecting mirror has the form of a ring having an axis coinciding with the optical axis. Plural laser beam detecting elements are disposed on the inner peripheral area of the ring. The angular positions of the mirrors are controlled such that a difference in outputs of the detecting elements is minimized.

Abstract: A laser apparatus has a phase regulator for regulating phase of output laser beam is provided, in which a full reflection portion of an output mirror is made partially reflective and a relative optical length thereof to a non-reflection portion of the output mirror is regulated by a relative thickness thereof. In one aspect of the invention, a coating provided on a center portion of an inner surface of an output mirror of a resonator comprises a partially reflective coating and a phase difference between laser beam portions passing through the center portion and a surrounding portion is regulated by a thin membrane having same refraction index as that of a matrix of the output mirror and provided between the matrix and a coating on either surface of the output mirror.

Abstract: A gas laser device comprises a discharge tube made of a dielectric material; a laser medium gas which is circulated at a high speed within the discharge tube in the axial direction of the discharge tube; an optical resonator composed of a total refelection mirror and a partial reflection mirror, both being disposed in mutual confrontation at both ends of the discharge tube; a plurality of electrodes oppositely provided on the outer periphery of the discharge tube; and a power source for applying an a.c. voltage to the oppositely provided electrodes to generate silent discharge.

Abstract: A silent discharge type pulse laser device having a pair of opposing electrodes, at least one of which is an electrode covered by a dielectric, which is mounted opposite to a metallic electrode with a silent discharge space in between, a laser resonator consisting of a total reflection mirror and a partial reflection mirror mounted opposite to each other with the silent discharge section in between, a source of high frequency voltage for supplying to the pair of electrodes a high frequency voltage having a predetermined period for silent discharge, and a controller for controlling the high frequency voltage from the source with respect to a first interval and a second interval that form a period longer than the period for silent discharge.

Abstract: A silent discharge-type laser device in which silent discharge is established to produce a laser output by applying a high-frequency voltage across a set of opposing electrodes, at least one of the electrodes being a dielectric electrode; signals which are fed to the power source which produces a high-frequency voltage, used to modify the amplitude of the high-frequency output or to modify the frequency of the high-frequency output. According, the output voltage produced by the high-frequency power source can be increased or decreased at high speeds.

Abstract: A silent discharge gas laser apparatus has three or more electrodes arranged in axial symmetry with the laser radiation axis and supplied with voltage from a multi-phase high frequency power source to establish a continuous discharge and a higher discharge density at reduced frequencies, particularly in the central region of the discharge zone.

Abstract: A silent discharge gas laser comprises an earthing electrode and a high voltage electrode whose discharge surface is covered with a dielectric and a power source for applying an AC high frequency high voltage to excit a laser gas. The power source periodically and intermittently applies high frequency voltage to turn on and off to give high peak value.

Abstract: A silent discharge type gas laser device comprises a high voltage side electrode and a low voltage side electrode which are disposed through a discharge space wherein substantial surface area of at least one of the electrodes is covered with a dielectric and an equivalent diameter of the covered dielectric is less than several times the length of the discharge space.

Abstract: An ozone generating apparatus is disclosed which is quite compact and has a high yield of ozone and which prevents an abnormal rise of temperature in a discharge gap by recycling a liquid coolant having low electric conductivity through an inner part of a high voltage electrode tube of a silent discharge ozonizer to cool the electrode tube.